Solar power may be used to produce electricity by using mirrors to concentrate solar radiation on one or more receivers. In some examples, the sunlight heats a fluid in a receiver, producing a heated, pressurized fluid (e.g. gas or a gas/liquid mixture) either directly by boiling the fluid, or indirectly by running the heated fluid through one or more heat exchangers to produce a heated pressurized fluid, such as steam. In some variations, steam can be used directly in applications that require process steam. In some variations, heated pressurized gas (e.g. steam) turns one or more turbines which power electrical generators. In other examples, the receiver includes one or more photovoltaic devices that absorb concentrated sunlight and directly generate electricity.
The mirrors used in such arrangements are often curved. Curved mirrors are conventionally formed by bending a mirror over a shaped form or mold, then adhering or otherwise attaching a support frame to the mirror, such that the mirror retains the shape of the form or mold after being attached to the frame. Forming mirrors by this technique is described in, for example, U.S. Pat. Nos. 4,268,332 and 4,239,344. Typical fabrication tolerances of mirrors formed by this technique are such that substantial optical errors can be introduced. In some cases, refining the fabrication tolerances to reduce errors may be prohibitively costly.